The Downton Abbey estate stands a splendid example of confidence and mettle, its family enduring for generations and its staff a well-oiled machine of propriety. But change is afoot at Downton - change far surpassing the new electric lights and telephone. A crisis of inheritance threatens to displace the resident Crawley family, in spite of the best efforts of the noble and compassionate Earl, Robert Crawley; his American heiress wife, Cora; his comically implacable, opinionated mother, Violet; and his beautiful, eldest daughter, Mary, intent on charting her own course. Reluctantly, the family is forced to welcome its heir apparent, the self-made and proudly modern Matthew Crawley, himself none too happy about the new arrangements.